This is true for a purely bilateral situation like US-China, but the situation is different if there are more parties involved. For example, the public policy d

This is true for a purely bilateral situation like US-China, but the situation is different if there are more parties involved. For example, the public policy drives what policy other countries have (mutual assurances). Policy also can’t be merely an oral statement it’s also action. A credible policy to defend Taiwan means massive investment in ability to do so. It’s what makes the bluff expensive enough to call at any odds.